CN101451946A - Method for implementing multi-substance detection by utilizing simple micromechanical cantilever beam - Google Patents

Abstract

The invention relates to a method of realizing multiple material testing through a single micromechanical cantilever and preparation of a cantilever, characterized in that, different specific recognition sensitive films are respectively deposited at which cantilever high order bending mode amplitude is zero and at a free end of the cantilever, through the characteristics when the amplitude is zero, quality detecting accuracy is zero under high order mode and the quality detecting sensitivity is largest at the free end, frequency variation before and after detection of each cantilever is recorded, quality of different materials adsorbed on each sensitive position is obtained, thereby realizing detecting multiple matters through the single cantilever. The invention is characterized by simple structure, convenient manufacture, easy implementation and good expansibility.

Description

Utilize simple micromechanical cantilever beam to realize the method that multiple material detects

Technical field

The present invention relates to a kind of simple micromechanical cantilever beam that utilizes and realize multiple material method for making that detect and semi-girder.The invention belongs to the micro mechanical sensor field.

Background technology

Sensor is the basis of measurement instrument and detection system.Traditional sensor comes non electrical quantities such as gaging pressure, temperature, displacement by changing electrical quantities such as resistance, electric capacity or inductance, and exports with the voltage and current signal.Need to increase A/D converter between sensor and control circuit, this has not only reduced reliability, response speed and the measuring accuracy of system, and has increased cost.The output quantity of resonant transducer is a frequency signal, precision and resolution height, and long-time stability are good, can realize interface with computing machine by simple digital circuit, thereby save complex structure, expensive A/D conversion equipment.The development resonant transducer, adaptation with the microprocessor be the digital control system at center be one of important directions of sensor development still, the resonant transducer that has now used (as humorous vibration cylinder, resonance beam, responant diaphragm, resonance bend pipe) physical dimension is bigger, complex structure, cost an arm and a leg, resonance frequency and sensitivity are low.Along with the development of microelectric technique and micromachining technology and the application in sensor,, caused people's special interest with the micromachine resonant sensor that micromachining technology produces.The sensitive element of micromachine resonant sensor is micro-cantilever, microbridge (two-end fixed beam), the square film harmonic oscillators such as (or diaphragms) of making of microelectronics and micromechanical process, utilize its resonance frequency, amplitude or phase place etc. as responsive measured parameter, can be used to physical quantitys such as gaging pressure, vacuum tightness, angular velocity, acceleration, flow, temperature, humidity and gas componant.The energisation mode of resonator has electric magnetization, static excitation, contrary piezoelectric excitation, electric heating excitation, photothermal excitation etc., and its detection mode (being the pick-up mode) has piezoelectricity pick-up, voltage dependent resistor (VDR) pick-up, electromagnetism pick-up, capacitor vibration pick-up, optics pick-up etc.

Semi-girder resonator one end is fixed, other end freedom, and the unrelieved stress that free end forms in beam in the time of can discharging element manufacturing, resonance frequency are not subjected to the influence of encapsulation stress.The shape of semi-girder resonator has vertical bar shaped, variable cross section vertical bar shaped, U-shaped beam, three cantilevered corner beams, tuning fork beam etc., is used widely on devices such as atomic force microscope (AFM) probe (rapping pattern and noncontact mode), micromechanics electronic filter, oscillator, biochemical sensor.

, have broad application prospects owing to have high resolving power, high sensitivity, characteristics such as response and digital output signal fast as the resonance type micromechanical cantilever beam sensor of mass-sensitive at aspects such as environmental monitoring, medical diagnosiss.The core component of this sensor is semi-girder and resonant drive and the sensitive element under the resonant condition.When by biochemical specificity absorption determinand being adsorbed on the semi-girder surface, the variation of semi-girder equivalent mass changes the semi-girder natural resonance frequency, by detecting this change of resonance frequency amount content of quantitative test determinand accurately.[N.V.Lavrik，M.J.Sepaniak，P.G.Datskos，Cantilever?transducers?as?a?platform?for?chemical?and?biological?sensors，Review?of?Scientific?Instruments，75，2229(2004)]。Semi-girder of traditional resonant mode cantilever beam sensor can only detect a kind of determinand, and in actual applications, because the test environment complexity is disturbed in order to get rid of cross reaction, often needs to detect simultaneously multiple different material.Solution in the past is to utilize many semi-girders to form array, and every semi-girder detects a kind of determinand.[R.McKendry，J.Zhang，Y.Arntz，et?al.，Multiple?label-free?biodetection?and?quantitativeDNA-binding?assays?on?a?nanomechanical?cantilever，Proceedings?of?the?NationalAcademy?of?Sciences，99，9783(2002)]。The shortcoming of this method is a complex structure, need to handle multiple signals, and the difference of structural parameters can cause the difference of quality testing sensitivity between the different semi-girder, has increased measuring error.

Summary of the invention

The purpose of this invention is to provide a kind of simple micromechanical cantilever beam that utilizes and realize sensor construction and its implementation that multiple material detects, to overcome the deficiency of cantilever array.Its basic thought and implementation method are as follows: be the surperficial sensitive membrane of distinguishing the different specific recognition of self-assembled growth of free end of zero place and semi-girder at semi-girder high-order mode of flexural vibration amplitude, utilizing amplitude is zero to be in that quality testing sensitivity is zero under the high order mode, and the characteristic of free end quality testing sensitivity maximum, the variation of the frequency before and after detecting of each mode by writing down semi-girder simultaneously, obtain the quality of the adsorbed different material of each sensitive position, thereby realize detecting multiple material with single semi-girder.

Measuring two kinds of materials with single strip semi-girder is example, and illustrate that ultimate principle of the present invention is as follows: the mode function of strip semi-girder n rank mode of flexural vibration is:

Wherein l is the length of semi-girder, and x is the coordinate on the semi-girder length direction, and κ is a constant that depends on semi-girder length, κ ₁L=1.875, κ ₂L=4.694 is as exponent number n〉2 the time, κ _nL=(n-0.5) π.The quality testing sensitivity of diverse location is different on the length direction of semi-girder, can be expressed as

ω wherein _nAnd m _EffBe respectively the n rank mode of flexural vibration resonance angular frequency and the effective mass of resonant mode semi-girder.The relative mass detection sensitivity of preceding two rank mode of flexural vibration with the curve of change in location as shown in Figure 1.As can be seen, it is zero limit (x=0.783l is called the N position) that second-order modal has a quality testing sensitivity from the figure, and the position of quality testing sensitivity maximum all is the free end (being called the E position) of semi-girder under the different modalities.When N position and E position have been adsorbed quality Δ m respectively _NWith Δ m _EAfter, the single order of resonance beam and second order mode of flexural vibration frequency all will reduce.Because the quality testing sensitivity of N position is zero, so the frequency change Δ ω of second-order modal ₂All be by Δ m _ECause, can release Δ m thus _ESize: Δ m _E=2m _EffΔ ω ₂/ ω ₂At this moment examine or check the frequency change of single order mode again: it changes simultaneously by Δ m _NWith Δ m _ETwo parts cause, and Δ m _EObtain, so by Δ ω ₁Can release Δ m _NSize: Δ m _N=2m _Eff(Δ ω ₁/ ω ₁-Δ ω ₂/ ω ₂)/0.493.Promptly by the frequency change of semi-girder single order and second order mode of flexural vibration before and after the record absorption, the absorption quality of diverse location just can obtain by solving equation group (1):

$\left\{\begin{array}{c}{\mathrm{\Δm}}_E={2m}_{\mathrm{eff}}{\mathrm{\Δ\ω}}_2/{\mathrm{\ω}}_2\\ {\mathrm{\Δm}}_N={2m}_{\mathrm{eff}}({\mathrm{\Δ\ω}}_1/{\mathrm{\ω}}_1-{\mathrm{\Δ\ω}}_2/{\mathrm{\ω}}_2)/0.493\end{array}\right.---\left(1\right)$

M in the formula _EffBe the effective mass of the n rank mode of flexural vibration of resonance beam, ω ₁And ω ₂Be respectively the frequency of single order mode and second-order modal, Δ ω ₁With Δ ω ₂Frequency change for single order mode and second-order modal;

According to top described principle, the self-assembled growth or apply the sensitive membrane (as Fig. 2) of different specific recognition respectively in the N position of semi-girder and E position, detect the relative variation of front and back semi-girder single order and second order mode of flexural vibration frequency by the sweep generator record, just can calculate two kinds of particular test absorption quality separately respectively, thereby realize " beam two is surveyed ".In like manner, it is zero to be that the mode of flexural vibration amplitude is the position at zero place that the high-order mode of flexural vibration all has quality testing sensitivity, choose each the quality testing sensitivity of 2 rank, 3 rank respectively and be zero the position and the fixing sensitive membrane that different specific recognition of end position of semi-girder up to the n rank, by monitoring each rank change of resonance frequency, just can realize " beam n survey ".

In sum, utilize simple micromechanical cantilever beam to realize the method that multiple material detects, it is characterized in that at semi-girder high-order mode of flexural vibration amplitude being the surperficial sensitive membrane of distinguishing the specific recognition of the different test substance of deposit of free end of zero place and semi-girder, obtain detecting each rank mode resonance frequency of front and back by frequency sweep, thereby calculate the absorption quality of different material.

Described simple micromechanical cantilever beam, its material can be crystal semiconductor (silicon, germanium, gallium arsenide), also can be silicon compound (monox, silicon nitride, silit etc.) or above multiple material is compound;

Described simple micromechanical cantilever beam, it is shaped as regular shape, as strip, variable cross section strip, U-shaped, T shape, triangle, tuning fork shape etc.;

Described simple micromechanical cantilever beam, its energisation mode can be electric magnetization, static excitation, contrary piezoelectric excitation, electric heating excitation and photothermal excitation, and its detection mode can be piezoelectricity pick-up, capacitor vibration pick-up, electromagnetism pick-up, light signal pick-up and voltage dependent resistor (VDR) pick-up.In order to realize above-mentioned concrete excitation/detection means, can on beam, make auxiliary layer, as reflector layer, metal connecting line electrode equal excitation or detecting element.But behind the increase auxiliary layer, the deposition location of its sensitive membrane need recomputate;

The deposit of the sensitive membrane of described specific recognition can be passed through self-assembled growth, also can be by instrument or the manual application that the point sample function is arranged.

What deserves to be mentioned is that the quality testing sensitivity of employed micromachine cantilever beam is depended in the quality testing sensitivity of the method that the present invention proposes, and the shape and size of semi-girder all are can be optional.By optimal design, its sensitivity can be very high, in addition reach fly the gram (10 ^-15G) magnitude realizes other detection of unimolecule level.Therefore the method for the present invention's proposition can be used in the trace materials detection.

This shows that major advantage of the present invention is:

(1) simple in structure: as to detect multiple material and only need use a semi-girder;

(2) realize easily: the resonance frequency of each rank mode can obtain by the sweep generator one-off scanning;

(3) systematic error is little: avoided cantilever array because the measuring error that structural parameters difference causes;

(4) favorable expandability: can realize the detection of different material by the different sensitive membrane of deposit, quality testing sensitivity changes with the semi-girder that uses, and can accomplish trace detection.

Description of drawings

Fig. 1 is the curve of the relative mass detection sensitivity of single order and second order crooked syntony mode with change in location.

Fig. 2 is as the single semi-girder synoptic diagram that detects two kinds of materials.

Fig. 3 is the manufacture craft flow process that the electric magnetization/pressure drag as one embodiment of the present of invention detects silicon cantilever.

Fig. 4 is the stereoscan photograph of the silicon cantilever of the electric magnetization/pressure drag detection as one embodiment of the present of invention.

Fig. 5 is that the electric magnetization/pressure drag as one embodiment of the present of invention detects silicon cantilever sensor testing circuit synoptic diagram.

What Fig. 4 and Fig. 5 illustrated only is to be used for electric magnetization/pressure drag detection method.Other excitation/detection meanss do not influence application of the present invention.

Among the figure:

The B-stationary magnetic field; The i-drive current; The F-Lorentz force; The 1-N position; The 2-E position; 3-sensitive membrane 1; 4-sensitive membrane 2; The 5-cantilever beam structure; The 6-silicon layer; The 7-silicon oxide layer; The Wheatstone bridge that the 8-voltage dependent resistor (VDR) is formed; 9-surface protection silicon oxide layer; The 10-drive coil; The 11-sweep generator; The 12-stabilized voltage supply; The 13-amplifier.

Embodiment

Several devices below by concrete enforcement are example, further illustrate substantive distinguishing features of the present invention and marked improvement, but the present invention are not limited only to described example.

Embodiment 1:TNT and sarin chemical sensor

Present embodiment is to make silicon micromachine resonant cantilever beam sensor that a kind of electric magnetization/pressure drag detects to realize a beam TNT (trinitro-toluene) to be detected with Schain poison gas the time.TNT and sarin are two kinds of great dangerous material of harmfulness, all once are used as the attack of terrorism, cause serious consequence.Effectively detect TNT and Schain poison gas, will provide technical support for the safety check and the anti-terrorism of transport hub such as airport, station, harbour, customs and primary location, significant to ensureing public safety.

The principle of work of this sensor is as follows: N position and E position deposit gold film on the semi-girder surface, on golden film, fix two kinds of sensitive membrane then respectively, and a kind of have the selection adsorbability to TNT, as 11MUA (sulfydryl 11 acid); And another kind has the selection adsorbability to sarin, as sulfydryl 11 acid of copper complexing.When TNT or sarin were arranged in the environment, its molecule can be arrived the semi-girder surface by the sensitive membrane selective adsorption, thereby caused the decline of semi-girder single order and second order crooked syntony model frequency.Note single order, second order resonance frequency before and after the absorption, the just TNT and the sarin quality separately that can obtain adsorbing by formula (1) by sweep generator.Use highly sensitive semi-girder, just can detect the TNT and the sarin molecule of trace, thereby reach the function of an early warning.

The manufacture craft flow process of this semi-girder as shown in Figure 3, and details are as follows:

(a) adopt N type SOI (silicon on the insulator) silicon chip, top layer silicon is thinned to semi-girder thickness, thermal oxide forms

Oxide layer.

(b) make mask with photoresist, make the semi-girder front description by lithography, erode monox with buffered hydrofluoric acid and form the semi-girder figure; Make mask with photoresist, make the figure of sensitive resistance by lithography, adopt ion implantation technology to carry out the boron ion doping, activated the sensitive resistance that the boron ion formation of injecting has piezoresistive effect in 30 minutes 1000 ℃ of annealing, its square resistance is 200 ohm.

(c) make mask with photoresist, make pressure drag fairlead figure by lithography, erode monox with buffered hydrofluoric acid and form fairlead.Sputter thickness exists

Above aluminium film, photoetching successively, burn into remove photoresist, and form drive coil and pressure drag lead-in wire simultaneously.Form Ohmic contact in 480 ℃ of alloyings 30 minutes and pressure drag.Form silicon dioxide layer of protection in the positive PECVD (plasma reinforced chemical vapour deposition) of employing of silicon chip technology, make mask with photoresist, make the protective seam figure by lithography, remove unnecessary monox with RIE (reactive ion etching) technology.

(d) resist coating on silicon chip, photoetching development, the evaporated gold film adopts stripping technology to form gold thin film.The E position at gold thin film place and N position obtain through accurate Calculation, and utilize photoetching technique accurately to form.Adopt stripping technology again, on the gold thin film of E position, form one deck titanium film, block golden film fully.

(e) make mask with photoresist, photoetching forms the cantilever beam structure figure, adopts the positive etching of deep reaction ion etching technology, forms cantilever beam structure.Mask is made at the back side with photoresist, and dual surface lithography forms the back-etching figure, adopts deep reaction ion etching technology etching body silicon to the SOI intermediate oxide layer.

(f) erode the SOI intermediate oxide layer with buffered hydrofluoric acid, discharge cantilever beam structure, finish the semi-girder element manufacturing.

After semi-girder completes, the semi-girder gold surface is added hydrogen peroxide with the concentrated sulphuric acid clean, growth TNT sensitive membrane sulfydryl 11 acid on the golden film of N position then.Put into the titanium film that oxalic acid solution removes the E position afterwards.Oxalic acid is to not influence of 11 acid of the sulfydryl on the golden film.This moment, the golden film of E position exposed, and can drip sulfydryl 11 acid of coating the copper complexing by point sample instrument thereon.Complete to this resonant mode cantilever beam sensor that can realize " beam two is surveyed ".What deserves to be mentioned is that the selection of the sensitive membrane of N position and E stationkeeping is arbitrarily, sulfydryl 11 acid of the copper complexing of can growing in the N position, and in 11 acid of E position growth sulfydryl, to not influence of testing result.Fig. 4 has provided the stereoscan photograph of the micromachine cantilever beam that adopts making place of this method.

Test circuit such as Fig. 5.The sinusoidal wave swept-frequency signal that sweep generator provides is by the drive coil excitation cantilever arm beam vibration on the semi-girder, the Wheatstone bridge that voltage dependent resistor (VDR) is formed detects the crooked stress that produces of semi-girder, and it is converted into voltage signal, feed back to the amplitude-versus-frequency curve that sweep generator obtains the semi-girder vibration after amplifying by amplifier.Each rank resonance frequency of semi-girder be can obtain from the amplitude-versus-frequency curve, the TNT that adsorbs respectively two positions and the quality of sarin molecule just can be calculated by simple data processing.This example sensor to the detectable concentration lower limit of TNT and sarin molecule 10ppb (1/1000000000th).

Embodiment 2:AFP and CEA biology sensor

Present embodiment is to make silicon micromachine resonant cantilever beam sensor that a kind of electric magnetization/pressure drag detects to realize a beam AFP (alpha fetoprotein (AFP)) to be detected with CEA (carcinomebryonic antigen) time.AFP and CEA are important tumor markers, and wherein the tumour that mainly detects of AFP is a primary carcinoma of liver, also have carcinoma of testis, oophoroma etc.; And CEA mainly detects is digestive system carcinoma and lung cancer, breast cancer etc.Trace detection to these two kinds of antigens will play an important role to the human cancer early warning.

The principle of work of this sensor is as follows: N position and E position deposit gold film on the semi-girder surface, on golden film, fix two kinds of AFP antibody and CEA antibody then respectively.When semi-girder was dipped into the human body blood sample, AFP and CEA molecule can be arrived the semi-girder surface by its antibody selective adsorption, thereby caused the decline of semi-girder single order and second order crooked syntony model frequency.Note single order, second order resonance frequency before and after the absorption by sweep generator, the just AFP that can obtain adsorbing and CEA quality separately, thus help judges whether the blood sampling people has cancer hidden danger.

The semi-girder manufacture craft flow process of this sensor is with example 1, as shown in Figure 3.Its sensitive membrane method of modifying is different.At first AFP antibody is handled through tricarboxylic methyl acid phosphate (TCEP) and produced sulfydryl, thereby self-assembled growth is on the golden film of N position; Use bovine serum albumin(BSA) (BSA) with the do not grow site sealing of antibody of golden film then; Remove the titanium film of E position with oxalic acid, expose following golden film; Again with CEA antibody after tricarboxylic methyl acid phosphate (TCEP) is handled on the golden film of self-assembled growth in the E position.Because the golden film of N position is through the BSA sealing, CEA antibody can't be grown on the N position, has so just realized two kinds of antibody self-assembled growth separately.The position of same these two kinds of sensitive membrane of transposing does not influence detection.

The method of testing of this sensor is with example 1.Because employed micromachine cantilever beam sensor can reach monomolecular detection sensitivity, so early stage medical diagnosis on disease is had very application prospects.

Embodiment 3: ammonia, carbon monoxide, hydrogen chemical sensor

Present embodiment is to make silicon micromachine resonant single cantilever beam sensor that a kind of electric magnetization/pressure drag detects to detect when realizing a beam to ammonia, carbon monoxide, three kinds of gases of hydrogen.Ammonia, carbon monoxide, hydrogen all are common toxic or inflammable gas, in case leakage might cause tremendous loss, therefore need effective monitoring, be strictly on guard against leakage in factory.

The principle of work of this sensor is as follows: in the position of the fixed distance end 0.504l on semi-girder surface (be called the M position, the quality testing sensitivity of 3 rank mode of flexural vibration is zero on this position)) and N position and E position are fixing respectively ammonia, carbon monoxide and hydrogen a sensitive membrane of selecting adsorbability.When one of above-mentioned three kinds of gases (for example ammonia) were arranged in the environment, its molecule can be adsorbed on corresponding position (being the M position here) by selectivity, and the resonance frequency of first three rank mode of flexural vibration of semi-girder can change like this, two declines, and one is constant.What frequency was constant is the resonance mode of absorption position correspondence, and for example the words of M position are constant with regard to corresponding 3 rank resonance frequencies.Whether change and just can whether be had one of above three kinds of gases to reveal by measuring preceding 3 mode of flexural vibration resonance frequencies like this.If 3 frequencies all change, must there be a kind of gas of surpassing to reveal so.

The semi-girder manufacture craft flow process of this sensor is with example 1, and as shown in Figure 3, variation is to have increased a sensitive membrane position.The coating of selective sensitivity film can be dripped by point sample instrument and is coated with.Its method of testing is also with example 1.Utilize the high detection sensitivity of micromachine cantilever beam sensor, can be good at realizing the leak detection of factory above three kinds of inflammable, toxic gases.

Claims (9)

1, utilize simple micromechanical cantilever beam to realize the method that multiple material detects, it is characterized in that at simple micromechanical cantilever beam high-order mode of flexural vibration amplitude being the surperficial sensitive membrane of distinguishing the different test substance of deposit of free end of zero place and micromachine cantilever beam, obtain detecting each rank mode resonance frequency of front and back by frequency sweep, thereby calculate the absorption quality of different material.

2, realize the method that multiple material detects by the described simple micromechanical cantilever beam that utilizes of claim 1, it is characterized in that described micromachine cantilever beam is strip, variable cross section strip, U type, T type, triangle or tuning fork shape.

3, realize the method that multiple material detects by the described simple micromechanical cantilever beam that utilizes of claim 2, it is characterized in that the mode function of strip semi-girder n rank mode of flexural vibration is:

L is the length of semi-girder in the formula, and x is the coordinate on the semi-girder length direction, and k is a constant that depends on semi-girder length, k ₁L=1.875, k ₂L=4.694.

4, realize the method that multiple material detects by the described simple micromechanical cantilever beam that utilizes of claim 3, it is characterized in that as n 2 the time, k _nL=(n-0.5) π, the quality testing sensitivity table of diverse location is shown on the micromachine cantilever beam length direction:

ω wherein _nAnd m _EffBe respectively the n rank mode of flexural vibration resonance angular frequency and the effective mass of resonance beam.

5, realize the method that multiple material detects by the described simple micromechanical cantilever beam that utilizes of claim 3, it is characterized in that simple micromechanical cantilever beam single order and second order mode of flexural vibration amplitude are the N position and the simple micromechanical cantilever beam free end E position at zero place, by the frequency change of semi-girder single order and second order mode of flexural vibration before and after the record absorption, the adsorbance of diverse location is tried to achieve by following two formula:

$\left\{\begin{array}{c}{\mathrm{\Δm}}_E={2m}_{\mathrm{eff}}{\mathrm{\Δ\ω}}_2/{\mathrm{\ω}}_2\\ {\mathrm{\Δm}}_N={2m}_{\mathrm{eff}}({\mathrm{\Δ\ω}}_1/{\mathrm{\ω}}_1-{\mathrm{\Δ\ω}}_2/{\mathrm{\ω}}_2)/0.493\end{array}\right.$

Δ m in the formula _E, Δ m _NRepresent E position and N position absorption quality respectively, m _EffBe the effective mass of the n rank mode of flexural vibration of resonance beam, ω ₁And ω ₂Be respectively the frequency of single order mode and second-order modal, Δ _{ω 1}With Δ ω ₂Frequency change for single order mode and second-order modal.

6, realize the method that multiple material detects by the described simple micromechanical cantilever beam that utilizes of claim 1, it is characterized in that high-order mode of flexural vibration mode amplitude is the position at zero place, choose each the quality testing sensitivity of 2 rank, 3 rank respectively and be zero position, realize that by detecting each rank change of resonance frequency a beam n surveys up to the n rank.

7, realize the method that multiple material detects by the described simple micromechanical cantilever beam that utilizes of claim 1, it is characterized in that the sensitive membrane at the free end surface deposit test substance of micromachine cantilever beam is by self-assembled growth, the instrument that the point sample function is arranged or manual application.

8, realize the method that multiple material detects by each described simple micromechanical cantilever beam that utilizes in the claim 1～5, it is characterized in that:

1. the material of described semi-girder is the compound of silicon, germanium, gallium arsenide, monox, silicon nitride, silit or above multiple material;

2. described semi-girder energisation mode is electric magnetization, static excitation, contrary piezoelectric excitation, electric heating excitation or photothermal excitation;

3. the detection mode of described semi-girder is piezoelectricity pick-up, capacitor vibration pick-up, electromagnetism pick-up, light signal pick-up or voltage dependent resistor (VDR) pick-up.

9, making is characterized in that as the method for each described micromachine cantilever beam of claim 1～6 making step of silicon micromachine cantilever beam is:

(a) adopt N type soi wafer, top layer silicon is thinned to semi-girder thickness, thermal oxide forms 2000

Oxide layer;

(b) make mask with photoresist, make the semi-girder front description by lithography, erode monox with buffered hydrofluoric acid and form the semi-girder figure; Make mask with photoresist, make the figure of sensitive resistance by lithography, adopt ion implantation technology to carry out the boron ion doping, activated the sensitive resistance that the boron ion formation of injecting has piezoresistive effect in 30 minutes 1000 ℃ of annealing, its square resistance is 200 ohm;

(c) make mask with photoresist, make pressure drag fairlead figure by lithography, erode monox with buffered hydrofluoric acid and form fairlead; Sputter thickness is 7000

Above aluminium film, photoetching successively, burn into remove photoresist, and form drive coil and pressure drag lead-in wire simultaneously; Form Ohmic contact in 480 ℃ of alloyings 30 minutes and pressure drag; Form silicon dioxide layer of protection in the positive plasma reinforced chemical vapour deposition technology that adopts of silicon chip, make mask with photoresist, make the protective seam figure by lithography, remove unnecessary monox with reactive ion etching process;

(d) resist coating on silicon chip, photoetching development, the evaporated gold film adopts stripping technology to form gold thin film; The E position at gold thin film place and N position obtain through accurate Calculation, and utilize photoetching technique accurately to form; Adopt stripping technology again, on the gold thin film of E position, form one deck titanium film, block golden film fully;

(e) make mask with photoresist, photoetching forms the cantilever beam structure figure, adopts the positive etching of deep reaction ion etching technology, forms cantilever beam structure; Mask is made at the back side with photoresist, and dual surface lithography forms the back-etching figure, adopts deep reaction ion etching technology etching body silicon to the SOI intermediate oxide layer;

(f) erode the SOI intermediate oxide layer with buffered hydrofluoric acid, discharge cantilever beam structure, finish the semi-girder element manufacturing.

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